How planets come together

This Halloween brought more than tricks, for MIT planetary scientist Benjamin P. Weiss, October 31 marked the day his and five colleagues' work on the connection between meteorites and the records they hold regarding magnetic fields and the early history of planets. Talk about a treat!

Published in Science magazine, the study found that during the formation of the solar system, dust and rubble in a disk around the sun collided and stuck together to eventually form our planets, on the big scale. On the small-side, the tiny rocks which formed the larger planets first had the ability to melt, something past theorists did not believe. Weiss discovered that these mini planets could melt in such as way as to form those large chunks of rock, also known as planetesimals, and thereby force their constituents to spread out. This created lighter materials which formed a crust, while iron-rich materials entered the middle inside that crust, developing into a magnetic dynamo.

Weiss and his team now can study these bits of magnetic fields produced by such dynamos, by looking at meteorites, the broken off bits of planets. For Weiss, this is just a piece of the larger puzzle on understanding how magnetic fields form. By grasping that small planetesimals were themselves miniature planets at one time, Weiss thinks this could change how theorists believe large-scale planets like earth were born.

To learn more about this topic, head to MIT News.